Hidden Empire - This is a sequel to Card's Empire (one of the books of his I didn't really like).

Stonefather - novela by Orson Scott Card is the prelude to a forthcoming fantasy saga: Mithermages. A very enjoyable read that reminds me of some of his earlier fantasy work. It is a bit expensive, waiting for a paperback or Kindle release may make sense.

Keeper of Dreams - collects 22 short stories by Orson Scott Card, not found in Maps in a Mirror, including: The Elephants of Poznan, Keeper of Lost Dreams, The Yazoo Queen, Waterbaby and Angles. Published in 2008.

Ender in Exile. This is a direct sequel to Ender's Game (or to be technical it takes place between chapters 14 and 15 in Ender's Game). See all the books from the Ender's Game series and the story order for those books.

Empire by Orson Scott Card. "The American Empire has grown too fast, and the fault lines at home are stressed to the breaking point. The war of words between Right and Left has collapsed into a shooting war, though most people just want to be left alone. The battle rages between the high-technology weapons on one side and militia foot soldiers on the other, devastating the cities and overrunning the countryside. But the vast majority, who only want the killing to stop and the nation to return to more peaceful days, have technology, weapons, and strategic geniuses of their own."

Crystal City by Orson Scott Card, 2003, book six in the Alvin Maker series. "Alvin's efforts to protect his friends by keeping them healthy will create more danger than he could ever have suspected. And in saving the poor people of the city, Alvin will be put to the greatest test of his life---a test that will draw on all his power. For the time has come for him to turn to his old friend Tenskwa-Tawa, the Red Prophet who controls the lands to the west of the Mizzippy. Now Alvin must take the first steps on the road to the Crystal City that was shown to him in a vision so long ago."

Robota by Doug Chiang and Orson Scott Card , 2003. An original illustrated science fiction novel, Robota follows the fortunes of a strangely powerful amnesiac named Caps as he navigates an ancient, decaying world in which a dwindling human population battles a society of merciless robot warriors.

The Dragon Quintet edited by Marvin Kaye includes a novela by Orson Scott Card, a gothic yarn set in contemporary suburbia. "In the Dragon's House" tells about the mysterious dragon that lives in the wiring of an old house, palpable only to a young boy who in dreams shares its body and feels its true size and power. But what does it really want? Published in 2003 the book also contains stories by Michael Swanwick, Mercedes Lackey, Elizabeth Moon and Tanith Lee.

Shadow Puppets, Orson Scott Card, 2002. 30% off. In Shadow Puppets, Orson Scott Card continues the storyline of Shadow of the Hegemon, following the exploits of the Battle School children, prodigies who have returned to an Earth thrown into chaos after the unifying force of the alien invasion they stopped in Ender's Game and Ender's Shadow has dissipated. Read the first 3 chapters online.